THE CRANIAL NERVES 283 



3. The Inferior Maxillary Branch after its exit from the 

 cranium is a mixed nerve, supplying motion to the muscles of 

 mastication as well as common sensation to the parts presently 

 to be noted, and special sense to a part of the tongue. Its large 

 or sensory root comes from the Gasserian ganglion to be joined 

 just beneath the base of the skull by the small motor root which 

 has passed under the ganglion. Almost immediately this com- 

 mon trunk divides into (a) anterior and (b) posterior branches, 

 but first gives off a recurrent meningeal branch and a branch to 

 the internal pterygoid muscle. 



(a) The anterior of the two divisions of the inferior maxillary 

 nerve receives nearly the whole of the motor root and divides 

 into branches which supply the muscles of mastication, except- 

 ing the internal pterygoid and the buccinator. 



(b) The posterior division, chiefly sensory, divides into the 

 auriculo-temporal, lingual and inferior dental branches. 

 The auriculo-temporal branch runs backward to a point 

 internal to the neck of the condyle of the inferior maxilla, then 

 passing upward under the parotid gland divides into branches, 

 which are distributed to the external auditory meatus, parotid 

 gland, integument of the temporal region and of the ear and 

 surrounding parts. It communicates with the otic ganglion. 

 The lingual branch is joined by the chorda tympani, passes to 

 the inner side of the ramus of the jaw, crosses Wharton'sduct, 

 and is distributed to the papillae and mucous membrane of the 

 tongue and mouth. It communicates with the facial through 

 the chorda tympani, with the hypoglossal, and with the sub- 

 maxillary ganglion. The inferior dental branch passes be- 

 tween the internal lateral ligament and ramus of the jaw to enter 

 the inferior dental foramen. Thence it traverses the dental 

 canal in the inferior maxilla to issue at the mental foramen. 

 Here it divides into incisor and mental branches; the former con- 

 tinues in the bone to supply the incisor and canine teeth; the 

 latter supplies the skin of the chin and lower lip. In its course 



